A web-based questionnaire on the treatment of clinical mastitis in dairy cows was sent to 741 Swedish veterinarians who, according to the Swedish Department of Agriculture, had reported that they treated cases of mastitis in 2012. The aim of the study was to examine how veterinarians in Sweden treat clinical mastitis in dairy cows. The number of respondents who were enrolled in the study was 267, which represents a response rate of 36%. The questionnaire consisted of general questions about treatment of clinical mastitis in dairy cows and three specified cases where case A was a moderate, exacerbative clinical mastitis, case B was a severe, acute clinical mastitis and case C a moderate, acute clinical mastitis.Systemic treatment with antibiotics was the most common route of administration and penicillins were the most common substances to treat with. The proportions of veterinarians who stated that they would initiate systemic antibiotic treatment at the visit on the farm were 27%, 71% and 46% in case A, B and C, respectively. The proportion that said that they would start treatment with antibiotics directly on the first visit and would combine systemic and local treatment was 9%, 16% and 19% in case A, B and C respectively. Only a few veterinarians stated that they would treat only with local therapy. The proportions who stated that they would await the bacteriological culture were 56%, 10% and 34% in case A, B and C respectively. It was only in cases A and B that veterinarians indicated that they considered that the case did not require treatment with antibiotics, the proportion was 7% and 2% in cases A and B. Fifty six percent, 10% and 34% in case A, B and C, respectively, stated that they would await the results from the bacteriological culture before considering any antibiotic treatment. If growth of E. coli, the majority (>90%) in all three cases chose not to treat with antibiotics. If growth of S. aureus, 48 %, 96% and 83% in case A, B and C, respectively, stated that they would treat with some sort of antibiotics. This means that in case A (exacerbative mastitis) 52% did not initiate treatment with antibiotics. Of the veterinarians who indicated that they would treat with antibiotics 48% , 44% and 51% stated in case A, B and C, respectively, that they would treat with systemic antibiotics. Fifty percent, 56% and 47% in case A, B and C, respectively, stated that they would treat with a combination of systemic and local antibiotics. If growth of streptococci 78%, 100% and 91% in case A, B and C, respectively, stated that they would treat the case with some sort of antibiotics. Of these veterinarians 62%, 65% and 67% in case A, B and C, respectively, stated that they would treat with systemic antibiotics. Fifty two percent, 31%, and 27% in case A, B and C, respectively, stated that they would treat with a combination of systemic and local antibiotics. There was 8%, 4% and 6% in cases A, B and C respectively who stated that they only would administer local treatment with antibiotics if the bacterial culture showed growth of streptococci. The proportion of veterinarians who indicated that they would not treat with antibiotics was 22% and 9% in cases A and C, while no veterinary chose this option in case B. Antibiotic treatment was in most cases combined with anti-inflammatory treatment with NSAIDs although there were significant differences between different categories of veterinarians in how often they were used. It was also commonly stated among the veterinarians that they usually recommended the animal owner to use frequent milk-outs. The treatment of clinical mastitis in Sweden appears, in general, to follow the current recommendations and policy documents that are available although some exceptions were found that may need to be addressed. Nearly 80% of the veterinarians indicated the current policy regarding antibiotic treatment of cattle from the Swedish Veterinary Society as an important source of knowledge of antibiotic treatment of mastitis.